The invention relates to an arrangement in connection with extrusion tools, which comprises a nozzle structure consisting of axially arranged nozzle elements. The nozzle elements are arranged to form one or more layers covering a flexible elongated element on the surface of the flexible elongated element, which passes through the innermost nozzle element. The head section of the innermost nozzle or a separate guide member is used for controlling the flexible elongated element as it is passed through the nozzle structure. During manufacturing cables or the like elongated elements, one or more layers of material are provided over the cable or the like by extrusion tools. When the cable type, for example the diameter of a cable, to be manufactured is changed, the nozzle structure of the extrusion tool needs to be altered to be suitable for the diameter of the new cable type. A prior art solution for altering the nozzle structure is put forward in U.S. Pat. No. 6,827,568. In this solution the nozzle is provided with a separate guide member that may be changed according to the type of cable to be manufactured. The joint between the guide member and a nozzle element of the nozzle structure is arranged to be loosened by repulsive force acting on the unit in the direction of the flexible elongated element. The guide member is arranged to exit the nozzle structure in the direction of the flexible elongated element.
The drawback of the prior art is that in order to avoid back flow of molten material during tool change, the extrusion tool cannot utilize pressure type extrusion, but must be of tube or semi-tube type. As a consequence, adhesion of material to the conductor and filling of the space between the strands is unsatisfactory. Furthermore, the extrusion tool has to rely on gripping elements to hold the guide member in place. Thus the operation of the gripping mechanism under production conditions cannot always be guaranteed, resulting in a reduced reliability of the process, with, as a consequence, significant downtime and loss of productivity.